Telephone conference calls allow multiple parties to participate in a single conversation. Conference calls couple a plurality of locations (usually more than two) with use of a communication channel. At each location, there may be one or more parties (participating persons) to the conversation. Each location may include, for example, a conventional telephone set used by a single party, or a conventional speakerphone used by one or more parties. The communication channel supporting a conference call typically comprises a conventional switched telephone network. Should the communication channel include a wireless (e.g., cellular) communication link, one or more of the participating "locations" may comprise a mobile cellular phone or speakerphone.
Although a widely used tool in business and industry, telephone conference calls suffer from certain problems which impact on their effectiveness as a substitute for other methods of communication, such as a face-to-face meeting. For example, during a typical conference call, a party cannot be sure who else is on the line (Le., connected) at any given time. Moreover, unless a listener is familiar with the voice of each participant in the call, it may be unclear which party is speaking at any given time. Questions such as "John, are you still on the line?" or "Who just said that?" need to be asked frequently. Such difficulties can cause the conversation to become less productive and often uncomfortable or even embarrassing.